Calibration circuit and calibration method of wireless transceiver

Abstract

A calibration circuit and a calibration method for a wireless transceiver are provided. The wireless transceiver includes a transmission path and a reception path, and the transmission path includes a radio frequency (RF) circuit and a baseband amplifier. The calibration method includes the following steps: setting a target gain of the RF circuit according to a first gain setting value; receiving a first input signal through a coupling path and the reception path; measuring first power of the first input signal; setting the target gain of the RF circuit according to a second gain setting value; receiving a second input signal through the coupling path and the reception path; measuring second power of the second input signal; calculating a power difference between the first power and the second power; and adjusting at least one of the baseband amplifier and a digital circuit according to the power difference.

What is claimed is: 
     
       1. A method for calibrating a wireless transceiver that includes a transmission path and a reception path, the transmission path includes a radio frequency (RF) circuit and a baseband amplifier, the method comprising:
 (A) setting a target gain of the RF circuit according to a first gain setting value; 
 (B) receiving a first input signal through a coupling path and the reception path; 
 (C) measuring first power of the first input signal; 
 (D) setting the target gain of the RF circuit according to a second gain setting value; 
 (E) receiving a second input signal through the coupling path and the reception path; 
 (F) measuring second power of the second input signal; 
 (G) calculating a power difference between the first power and the second power; and 
 (H) adjusting at least one of the baseband amplifier and a digital circuit according to the power difference. 
 
     
     
       2. The method of  claim 1  further comprising:
 iterating step (A) to step (H); 
 wherein the first gain setting value of step (A) in a second iteration is the second gain setting value of step (D) in a first iteration prior to the second iteration. 
 
     
     
       3. The method of  claim 2 , wherein step (A) to step (H) are performed N times where N+1 gain setting values are processed in sequence, N being an integer greater than 1, and gains corresponding to the N+1 gain setting values are arranged in ascending or descending order. 
     
     
       4. The method of  claim 1 , wherein the coupling path is coupled between the transmission path and the reception path and comprises an attenuator. 
     
     
       5. The method of  claim 1 , wherein the transmission path is coupled to a first antenna, the reception path is coupled to a second antenna, and the coupling path is a wireless transmission between the first antenna and the second antenna. 
     
     
       6. A circuit for calibrating a wireless transceiver that includes a reception path and a transmission path including a radio frequency (RF) circuit and a baseband amplifier, the circuit is configured to performing following steps for calibrating the wireless transceiver:
 (A) setting a target gain of the RF circuit according to a first gain setting value; 
 (B) receiving a first input signal through a coupling path and the reception path; 
 (C) measuring first power of the first input signal; 
 (D) setting the target gain of the RF circuit according to a second gain setting value; 
 (E) receiving a second input signal through the coupling path and the reception path; 
 (F) measuring second power of the second input signal; 
 (G) calculating a power difference between the first power and the second power; and 
 (H) adjusting at least one of the baseband amplifier and a digital circuit according to the power difference. 
 
     
     
       7. The circuit of  claim 6  further performing following steps:
 iterating step (A) to step (H); 
 wherein the first gain setting value of step (A) in a second iteration is the second gain setting value of step (D) in a first iteration prior to the second iteration. 
 
     
     
       8. The circuit of  claim 7 , wherein step (A) to step (H) are performed N times where N+1 gain setting values are processed in sequence, N being an integer greater than 1, and gains corresponding to the N+1 gain setting values are arranged in ascending or descending order. 
     
     
       9. The circuit of  claim 6 , wherein the coupling path is coupled between the transmission path and the reception path and comprises an attenuator. 
     
     
       10. The circuit of  claim 6 , wherein the transmission path is coupled to a first antenna, the reception path is coupled to a second antenna, and the coupling path is a wireless transmission between the first antenna and the second antenna.